Nucleation and growth rates of ammonium chloride in organic media: Development of an on‐line measurement technique

Nucleation and growth rates of small ammonium chloride crystals precipitated from organic mother liquors were measured with an electronic particle counter using an on‐line measurement and data reduction technique. Current values for nucleation and growth rates could be obtained within a period of 3 min, thus permitting rapid scanning of variables affecting crystal size distribution. Population average sizes of 1 to 3μ were typically measured in these organic liquors. The average size of particles increased with increase in ammonium chloride solubility. Addition of surfactants (sodium dodecylbenzene sulfonate, sodium oleate) either had no effect on nucleation or inhibited growth and nucleation equally, thus did not change particle size. The average size of particles was slightly increased with addition of magnesium chloride.